Abstract: A novel sensing system and methods for preventing damage to the cochlea during cochlear implant surgery are disclosed, using optical sensing to determine the distance of a stylet or the end of the implant itself from the interior wall of the scalar tympani. A variety of feedback methods are proposed to enable the surgeon to perform the procedure safely without damage to the basilar membrane or other delicate anatomic structures. Although a number of embodiments are disclosed, one preferred embodiment comprises a robotically manipulated end-effector.

Abstract: A cochlear implant arrangement is described for creating sound perception in an implanted patient. An implant electrode contains electrode wires for carrying stimulation signals to corresponding electrode contacts distributed along a length of an outer surface of an apical electrode array section of the implant electrode. An apical portion of the electrode array is characterized by a tendency to fold back against a more basal section of the electrode array when inserted into a cochlea of the patient. An implantable stimulation processor produces the stimulation signals such that each electrode contact, including any in a folded back portion, delivers stimulation signals for a frequency band defined based on a function of spatial spread of stimulation voltage and correctly associated with tonotopic frequency response of the adjacent neural tissue.

Abstract: Method and apparatus for optically stimulating neurons of a plurality of auditory nerve pathways of a person to provide auditory sensations for the person including generating a plurality of pulsed light signals having one or more successive pulses; delivering the plurality of pulsed light signals to one or more auditory nerve pathways of the cochlea of the person; selectively controlling the plurality of light signals to optically stimulate and trigger nerve action potentials (NAPs) in the one or more auditory nerve pathways, wherein the selectively controlling includes empirically testing the delivering of the plurality of light signals and determining which optical-stimulation parameters used during the testing are most effective for optically stimulating the auditory nerve pathways of the person, and using results of the testing such that the delivering includes delivering the plurality of light signals with the optical-stimulation parameters that were determined to be most effective for optically stimula

Abstract: An implantable electrode is described for a cochlear implant patient with a malformed common cavity cochlea having a single internal cavity defined by an outer cavity wall or patients having an incomplete partition or conventional spiral-shaped cochlea. An intra-cochlear electrode array is configured to be inserted into the cochlea through a single cochleostomy opening. Outer array branches are closable about a center axis and the electrode array is configured to be closed into a single tube including the array branches for insertion through the single cochleostomy opening into the internal chamber of the cochlea. The electrode array opens within the internal cavity after insertion into the cochlea so that the array branches move away from the center axis to lie with their outer surfaces against the outer cavity wall to deliver the electrical stimulation signals through the stimulation contacts to adjacent neural tissue for auditory perception by the patient.

Abstract: Fluidic conductors deliver electrical signals to targeted locations within an organ. Both the insulating materials and conductive media components of the fluidic conductors are ultra-flexible. The small size of the fluidic conductors makes the technology particularly applicable to auditory prostheses, for example, cochlear implants, that deliver electrical signals to very discrete locations within the cochlea.

Abstract: Assessment of neuron excitation is implemented by quantifying the interaction between focused and unfocused stimulation applied to a cochlear array. By applying focused and unfocused stimulation to the electrode array and comparing the difference in the responses to the two types of stimulation the interaction may be determined. The magnitude of the interaction may be related to neural excitation and using this data a neural excitation profile may be determined.

Abstract: A cochlear implant electrode includes an implantable array carrier made of flexible material with electrode contacts distributed on its outer surface along a longitudinal axis. Electrode wires are embedded within the array carrier, each electrode wire having a terminal end electrically connected to a corresponding electrode contact for applying electrical stimulation signals carried by the electrode wires to adjacent neural tissue within the cochlea. Each electrode wire has an inner non-crystal conductive material surrounded by a flexible outer seal. The flexible material of the array carrier is configured to be reactive with the non-crystal conductive material of the electrode wires so that if a break occurs in the outer seal of an electrode wire that allows contact between the flexible material and the non-crystal conductive material, then a local leakage seal will form at the break that resists migration of the non-crystal conductive material to the outer surface of the array carrier.

Abstract: An exemplary cochlear implant system includes a sound processing assembly configured to be external to a patient and first and second extension members coupled to the sound processing assembly. The sound processing assembly includes a sound processing unit configured to process an audio signal and transmit one or more control parameters based on the audio signal to an implantable cochlear stimulator and a battery module configured to be electrically coupled to the sound processing unit and provide operating power to the sound processing unit. The first extension member has a distal portion configured to be coupled to a first ear of the patient and the second extension member has a distal portion configured to be coupled to a second ear of the patient. The first and second extension members typically extend back from the ears, thus positioning the sound processing assembly behind the patient's head.

Abstract: The present invention relates to the use of electrochemistry to control and generate specific user defined chemical reactions in regions that may be defined by electrode placement and geometry. In one embodiment, the present invention provides a method of shape changing cartilage in a subject through potential-driven electrochemical modification of tissue (PDEMT) or use of a potential-driven electromechanical (EMR) device.

Abstract: An implantable fenestration electrode delivers electrical stimulation signals for treatment of Meniere's disease. An electrode lead contains one or more signal wires for carrying a stimulation signal. An electrode tip at a terminal end of the electrode lead is configured for placement within a fenestration opening in an outer surface of a bony labyrinth of a patient with Meniere's disease without penetrating or impairing intra-labyrinthine membranes or neural tissue, and is adapted to deliver the stimulation signal via intra-labyrinthine fluid to the intra-labyrinthine neural tissue.

Abstract: Presented herein is a shapeable coil cable for use in connection with an implantable medical device comprising first and second external components. The shapeable coil cable is a conformable and non-resilient member that is sufficiently pliable to accept a configuration set by a user and sufficiently rigid to retain the configuration set by the user.

Abstract: A method for sterile packaging of a surface modified implantable device includes irradiating a surface of the device such that the hydrophobicity of the surface is decreased and, optionally, the device is simultaneously sterilized. The surface of the sterile, surface-modified implantable device is then covered in a polar solution to prevent hydrophobic recovery of the surface.

Abstract: A cochlear stimulation device comprising an electrode array designed to provide enhanced charge injection capacity necessary for neural stimulation. The electrode array comprises electrodes with high surface area or a fractal geometry and correspondingly high electrode capacitance and low electrical impedance. The resultant electrodes have a robust surface and sufficient mechanical strength to withstand physical stress vital for long term stability. The device further comprises wire traces having a multilayer structure which provides a reduced width for the conducting part of the electrode array. The cochlear prosthesis is attached by a grommet to the cochleostomy that is made from a single piece of biocompatible polymer. The device, designed to achieve optimum neural stimulation by appropriate electrode design, is a significant improvement over commercially available hand-built devices.

Abstract: A malleable implantable medical device for implanting in a recipient comprising a flexible region of the medical device, one or more structures proximate to the flexible region, wherein the one or more structures is configured to provide a bending force to the flexible region, and one or more hermetically sealed medical components coupled to the flexible region, wherein the one or more medical components is configured to provide a therapeutic effect on the recipient.

Abstract: Exemplary systems and methods for loading a pre-curved electrode array onto a straightening member are described herein. An exemplary system may include a loading tool including a housing and a slider member disposed at least partially within the housing. The slider member may be slidable from a first position to a second position and configured to move a pre-curved electrode array from a curved configuration to a straightened configuration as it slides from the first position to the second position. The exemplary system may also include a straightening member configured to be inserted into the pre-curved electrode array. Corresponding methods are also described.

Abstract: An implantable nerve stimulation device has a sensor system, a data processor in communication with the sensor system, and a nerve stimulation system in communication with the data processor and constructed to provide electrical stimulation to at least one branch of at least one vestibulocochlear nerve. The nerve stimulation system includes an electrode array that has a first plurality of electrodes structured to be surgically implanted in electrical communication with a superior branch of the vestibular nerve, a second plurality of electrodes structured to be surgically implanted in electrical communication with a horizontal branch of the vestibular nerve, a third plurality of electrodes structured to be surgically implanted in electrical communication with a posterior branch of the vestibular nerve, and a common crus reference electrode structured to be surgically implanted into a common crus of the vestibular labyrinth.

Abstract: A novel electrode array is described for ear implant systems such as cochlear implants (CI) and vestibular implants (VI). The electrode array includes an electrode array core made of a flexible polymer material including an elongated helical portion having multiple helical turns. Electrode wires are embedded within the array core for carrying electrical stimulation signals. At a terminal end of each electrode wire, an electrode stimulation contact is exposed through the array core for applying the electrical stimulation signals to adjacent neural tissue. An electrode carrier of resilient material encases the electrode array and has an outer surface with contact openings exposing the stimulation contacts.

Abstract: The present invention provides methods for fabricating an electrode device component, the method comprising the steps of: (i) providing a biocompatible carrier material, and (ii) performing an ablative method on the biocompatible carrier material to form a recess, the recess capable of receiving a biocompatible electrode material. The components so fabricated are useful as carriers for biological electrodes, such as cochlear electrodes and nerve cuff electrodes.

Abstract: Exemplary systems for loading a pre-curved electrode array onto a stylet include a loading tool and a stylet retainer. The loading tool includes a docking assembly comprising a plurality of wing members that form a receptacle configured to receive a proximal portion of the stylet, a channel assembly comprising a channel configured to receive and allow passage therethrough of the pre-curved electrode array, the channel further configured to receive a distal portion of the stylet, and a connecting member configured to connect the channel assembly to the docking assembly. The stylet retainer is configured to couple to the loading tool to retain the stylet within the loading tool while the pre-curved electrode array is loaded onto the stylet. Corresponding methods are also described.

Abstract: An implantable antenna assembly includes a multilayer flexible printed circuit board comprising a first flexible substrate, second flexible substrate, and third flexible substrate. An inductor coil is formed by electrically conductive traces disposed on the first flexible substrate. A shield is formed by electrically conductive traces disposed on the second flexible substrate and third flexible substrate, the shield surrounding the inductor coil. A method for forming an implantable antenna assembly is also provided.

Abstract: A cochlear implant system has an implantable portion that includes a stimulator module for producing for the auditory system of a user an electrical stimulation signal representative of an acoustic signal. The implantable portion further includes a battery for supplying power to the stimulator module, a receiver module for receiving an electrical power signal across the skin of a user, and a recharge module that uses the electrical power signal to recharge the battery. The recharge module recharges the battery at less than the maximum recharge rate.

Abstract: An electrically powered device (160) including an insertion component (165) for insertion into the ear cavity of a user, the device (160) including at least one inductor (170) operatively connected to a control circuit (175), the control circuit (175) providing electrical energy to the at least one inductor (170) wherein the insertion component (165) includes the at least one inductor (170) such that when in use, the at least one inductor (170) is in close proximity to the inner ear of the user.

Abstract: A BTE prosthetic device for use in a medical system or prosthesis comprises a connector configured to mechanically attach an auxiliary device of the system to the BTE prosthetic device. The connector is electrically connected to an transceiver of the BTE prosthetic device. The connector operates as an electromagnetic antenna for transmitting and/or receiving signals between the BTE prosthetic and other components of the medical system.

Abstract: A cochlear implant electrode includes an electrode carrier having an electrode array with a groove disposed in a longitudinal direction along the electrode carrier, and a stopper positioned around the electrode carrier. The stopper has a protrusion on its inner surface that is configured to be positioned within the groove such that the stopper is movable with respect to the electrode carrier.

Abstract: An electrode array, having application as a cochlear implant, includes a tube formed of Parylene defining a hollow channel. A substrate formed primarily of Parylene is supported by the tube. In turn, a plurality of metallic electrodes and feed lines are supported by the substrate. Numerous voids are defined by the tube which opens into the hollow channel. The size and spacing of the voids regulate stiffness and curl of the tube to provide excellent fit within the cochlea.

Abstract: A device, including an implantable electronic circuit integrated at least one of in or on a substrate, wherein the device includes a hermetic enclosure having a space therein, wherein the substrate forms at least a portion of the hermetic enclosure.

Abstract: An exemplary system includes at least one computing device communicatively coupled to a cochlear implant system and that 1) determines one or more control parameters to be used by the cochlear implant system to apply electrical stimulation to a patient, 2) determines, based on the one or more control parameters, a target stimulation level to be used by the cochlear implant system to apply the electrical stimulation to the patient, and 3) displays a pre-stimulation visual cue indicative of the determined target stimulation level in a graphical user interface prior to the cochlear implant system using the one or more control parameters to apply the electrical stimulation to the patient. Corresponding systems and methods are also described.

Abstract: Exemplary loading tools configured to facilitate loading of a pre-curved electrode array onto a stylet include a docking assembly, a channel assembly, and a connecting member configured to connect the channel assembly to the docking assembly and maintain a distance therebetween. The docking assembly is configured to couple to the stylet. The channel assembly includes a channel configured to receive and allow passage therethrough of the pre-curved electrode array. The channel is aligned with the docking assembly such that when the stylet is coupled to the docking assembly, the stylet is located at least partially within the channel.

Abstract: Embodiments are generally directed to a feedthrough for an implantable medical device. The feedthrough comprises an insulator having one or more conductors extending therethrough that is hermetically connected (joined) to a housing of the implantable medical device. More specifically, the housing includes an aperture and the insulator is configured be positioned in the aperture. Braze material is configured to be positioned in one or more indentations in at least one of the housing or the insulator such that the braze material is disposed in the indentations between the insulator and the housing.

Abstract: An exemplary system includes a sound processor configured to 1) divide an audio signal into a plurality of analysis channels and 2) generate one or more tonality indices each representing a tonality of one of the analysis channels, and an implantable cochlear stimulator communicatively coupled to the sound processor and configured to 1) generate one or more stimulation pulses configured to represent the audio signal in accordance with one or more stimulation parameters, and 2) adjust the one or more stimulation parameters based on at least one of the tonality indices.

Abstract: An exemplary method of minimizing an effect of channel interaction among a plurality of channels in a multi-channel cochlear implant system includes empirically generating an electrical spread matrix that is specific to a patient and representative of a channel interaction among a plurality of channels defined by a plurality of electrodes of electrodes of a multi-channel cochlear implant system associated with the patient, generating a model electrical spread matrix that approximates the empirically generated electrical spread matrix and that has a band inverse matrix, and using the band inverse matrix to determine a set of stimulation current levels to be applied by way of a corresponding set of electrodes included in the plurality of electrodes in order to produce desired stimulation current levels at a plurality of stimulation sites within the cochlea in the presence of the channel interaction. Corresponding methods and systems are also disclosed.

Abstract: An intraneural implant comprises a lead comprising a number of electrode wires, a number of electrodes communicatively coupled to the electrode wires, the electrodes forming an electrode array, and an overmold surrounding the electrode wires and at least a portion of the electrodes, and a blunt dissector tip coupled to the lead to penetrate nerve tissues as the electrode array is implanted. An intraneural implant system comprises a flexible lead. The flexible lead comprises a lead body, an electrode array communicatively coupled to the lead body, a blunt dissector tip to penetrate a nerve bundle as the electrode array is implanted into the nerve bundle, and an implantation tool coupled to the electrode array to implant the electrode array into the nerve bundle.

Abstract: A microcircuit integrated cochlear electrode array and a process for the manufacture thereof, the electrode array comprising a multiconductor tail portion with longitudinally spaced outwardly exposed electrode receiving pads and a flat multiconductor head portion connected to the tail portion and having spaced outwardly exposed circuit attachment pads, the tail and head portions being laminated between a nonconductive film substrate and an insulating cover and the tail portion being helically wrapped into a helix with the electrode receiving circuit attachment pads exposed and carrying ring electrodes overmolded with a suitable polymeric material.

Abstract: A cochlear implant includes a processor, an array of electrodes disposed along a flexible body and a lead body connecting the processor to the array of electrodes. The lead body includes a first tube having a first outside diameter, a second tube having a second outside diameter smaller than the first diameter, a portion of the second tube being disposed within the first tube, and wires passing through the first tube and the second tube, the wires comprising a helically coiled portion. A method for forming a lead body is also provided.

Abstract: A system for cochlear implant surgery includes a reference device having at least a portion adapted to be arranged at a fixed position relative to a cochlea of a patient to provide a reference position, an image acquisition and processing system adapted to acquire an image of at least a portion of the cochlea relative to the reference position and to provide an implant plan based at least partially on the acquired image, and an implant system adapted for implanting a cochlear lead array using the reference position and the implant plan.

Abstract: A system and method of generating electrode stimulation signals for an implanted multi-channel electrode array of a cochlear implant includes processing an acoustic audio signal with a bank of filters. Each filter in the bank of filters is associated with at least one channel having an electrode. The bank of filters includes a first band pass filter that produces a broadband signal b(t) with frequencies that substantially cover at least one of a pitch frequency range of 100 Hz to 400 Hz and a first format range of 400 Hz-1000 Hz. At least one electrode associated with the first band pass filter is activated with electrode stimulation signals based, at least in part, on the broadband signal b(t). The filter bank may include at least one electrode associated with one or more filters other than the first band pass filter, the one or more filters producing signals having only higher frequencies than broadband signal b(t).

Abstract: A method for forming a cochlear electrode array with a plurality of electrodes which are spaced so as to stimulate sites within a cochlea includes shaping a sheet of electrically conductive material to form a support structure and a plurality of electrodes, in which the electrodes are tethered to the support structure at the spacing of the cochlear electrode array. A cochlear lead includes a flexible body that has frictional characteristics that vary about its circumference. A cochlear lead includes a flexible body with a first region and a second region with different surface textures. This generates differential sliding forces during insertion of the cochlear lead which influence a motion of the cochlear lead during insertion. The cochlear lead having an electrode array with varying stiffness along its length is also provided.

Abstract: An electrode lead for insertion into a patient's cochlea includes a substantially solid elongate carrier member having lateral and medial sides and opposing transverse surfaces extending between outer surfaces of the lateral and medial sides, wherein the carrier member has a thickness between outer surfaces of the lateral and medial sides, and a plurality of electrodes disposed on or in the medial side. A height of the lateral side between the transverse surfaces is generally greater than a height of the medial side between the transverse surfaces, wherein each of the heights is approximately perpendicular to the thickness.

Abstract: An ABI pad having a configuration and composition to provide the ABI pad with sufficient flexibility to permit the pad to be curved, molded or otherwise conformed to the cochlear nucleus, brainstem or other therapeutically-beneficial site, while ensuring the ABI pad maintains structural integrity over the anticipated operational life of the implant. The ABI pads are manufactured from silicone or other biocompatible material having a durometer sufficient to ensure the durability of the ABI pad over the anticipated operational life of the implant. To attain substantial flexibility, the thickness or cross section of the ABI pad is as minimal as possible to increase flexibility while not adversely affecting the noted durability of the pad. In one embodiment, the ABI pads are formed with an aperture in its interior region resulting in an ABI pad having minimal material mass while having sufficient structural integrity to reliably support the electrodes and associated wires.

Abstract: A cochlear stimulation device comprising an electrode array designed to provide enhanced charge injection capacity necessary for neural stimulation. The electrode array comprises electrodes with high surface area or a fractal geometry and correspondingly high electrode capacitance and low electrical impedance. The resultant electrodes have a robust surface and sufficient mechanical strength to withstand physical stress vital for long term stability. The device further comprises wire traces having a multilayer structure which provides a reduced width for the conducting part of the electrode array. The cochlear prosthesis is attached by a grommet to the cochleostomy that is made from a single piece of biocompatible polymer. The device, designed to achieve optimum neural stimulation by appropriate electrode design, is a significant improvement over commercially available hand-built devices.

Abstract: A cochlear implant includes an active base section with a front surface configured to lie against an inner modiolar wall of the scala tympani. Electrode contacts are on the front surface configured to face the inner modiolar wall to deliver electrode stimulation signals to nearby modiolar neural tissue. A passive apex section has a front surface without electrode contacts configured to lie against an outer lateral wall of the scala tympani. A U-shape transition bend section is at an apical end of the active base section bending in a reverse direction and transitioning into a basal end of the passive apex section such that the back surface of an apical tip of the passive apex section lies adjacent to a back surface of a basal end of the active base section at an electrode opening in the cochlea when the electrode is implanted in the patient.

Abstract: An exemplary system for loading a pre-curved electrode array onto a straightening member includes a loading tool and a straightening member. An exemplary loading tool may include a body and first and second flexible arms each having a fixed end connected to the body and a free end opposite the fixed end. The first and second flexible arms may define a straightening channel configured to constrain a pre-curved electrode array in a straightened configuration. The first and second flexible arms may be further configured to flex away from each other to receive the pre-curved electrode array into the straightening channel. The straightening member is configured to be inserted into the pre-curved electrode array while the pre-curved electrode array is in the straightened configuration and retain the pre-curved electrode array in the straightened configuration after the pre-curved electrode array is removed from the loading tool. Corresponding methods are also described.

Abstract: A vestibular prosthesis includes micro-electric-mechanical (MEMS) sensors, gyroscopes in each sensitivity axis (X, Y, Z), accelerometers in each sensitivity axis (X, Y, Z) to detect an angular and linear movement providing displacement measurements, gyroscopes in each one of the spatial axes (X, Y, Z), a microprocessor connected to the MEMS sensors and producing an electric pulse pattern or a continuous galvanic current pattern, a conditioning unit that amplifies and conditions the microprocessor output to apply current to the stimulation electrodes, the microcontroller being configured to determine the displacement of the cupula and the otolithic mass, determine a membrane potential as a result of a displacement detected by the MEMS sensors by means of determining a transduction current, and determine an action potential discharge pattern for the primary afferent neuron, which synapses with the hair cell by means of a mathematical model of the informative process of the vestibular mechanoreceptor.

Abstract: A microcircuit cochlear electrode array and process for the manufacture thereof, the electrode array comprising first and second flat microcircuits comprising a plurality of laterally spaced longitudinally extending electrical conductors and longitudinally spaced electrode receiving pads extending laterally from the conductors, the first flat microcircuit being helically wrapped in a first direction along an axis with its longitudinally spaced electrode receiving pads exposed on an end of an outer surface hereof and the second flat microcircuit helically being wrapped in an opposite direction on and along an outer surface of the first helically wrapped microcircuit with its longitudinally spaced electrode receiving pads exposed on an outer surface thereof adjacent the exposed longitudinally spaced electrode receiving pads of the first microcircuit, and ring electrodes around and electrically secured to the electrode receiving pads of the first and second microcircuits.

Abstract: Apparatus and method for triggering nerve-action potentials (NAPs) in each of a plurality of cochlear neurons in a cochlea of a person and in each one of a plurality of vestibular neurons in a vestibular organ of the person in order to provide auditory and balance sensations for the person, the method including generating a first plurality of light signals that stimulate a NAP in the selected cochlear neuron; delivering the first plurality of light signals to the selected cochlear neuron from within the cochlea; generating a second plurality of light signals that stimulate a NAP in the selected vestibular neuron; delivering the second plurality of light signals to the selected vestibular neuron from within the vestibular organ; and selectively controlling the first and second plurality of light signals to optically stimulate the selected cochlear and vestibular neuron in order to trigger NAPs of the selected cochlear and vestibular neuron.

Abstract: An implantable electrode array includes an elongated carrier (20) and a plurality of electrodes mounted within the carrier. A actuator adjusts the curvature of the carrier and can be controlled by varying an electric potential applied to the actuator. The actuator is based on an electrochemical cells and may be a conducting polymer based actuator.

Abstract: Method and apparatus for optically and electrically stimulating neurons of auditory nerve pathways of a person to provide auditory sensations for the person including generating a plurality of pulsed light signals having one or more successive pulses, delivering the plurality of pulsed light signals to one or more auditory nerve pathways of the cochlea of the person and selectively controlling the plurality of light signals to optically stimulate and trigger nerve action potentials (NAPs) in the one or more auditory nerve pathways. In some embodiments, the present invention also includes one or more electrical stimulation electrodes used to stimulate the low frequency portions of the auditory nerves.

Abstract: A novel electrode array is described for ear implant systems such as cochlear implants (CI) and vestibular implants (VI). The electrode array includes electrode wires for carrying electrical stimulation signals. At a terminal end of each electrode wire is an electrode stimulation contact for applying the electrical stimulation signals to adjacent neural tissue. An electrode carrier of resilient material encases the electrode wires and has an outer surface with a plurality of contact openings exposing the stimulation contacts. Multiple bend control elements are distributed along the length of the electrode array to control bending flexibility of the electrode array as a function of a bend radius threshold to be greater for bending less than the bend radius threshold and lesser for bending greater than the bend radius threshold.

Abstract: An apparatus including a flexible elongate carrier member configured to introduce a therapeutic element into the recipient and a stiffening member, permanently embedded in and longitudinally extending through at least a first region of said carrier member, configured to decrease said flexibility of said carrier member region so as to prevent deformation of said first region during implantation into the recipient.

Abstract: A vestibular stimulation electrode lead is described for conducting electrical stimulation signals generated by an implanted vestibular stimulation module. An extra-vestibular lead branch carries the stimulation signals from the stimulation module to a vestibular entry location. A stopper collar is bent away at a first discrete angle from a distal end of the extra-vestibular lead branch to penetrate into a vestibular structure at the entry location. An intra-vestibular electrode array is bent away at a second discrete angle from the stopper collar and has an outer surface with one or more electrode contacts for delivering the stimulation signals to vestibular neural tissue at a target location within the vestibular structure. The first and second discrete angles form a geometry of the stopper collar and intra-vestibular electrode array that limits insertion of the intra-vestibular electrode array beyond the target location within the vestibular structure.